Law on engine brakes should be enforced

After inquiring about the law concerning engine brakes on trucks, I was told by the police that it is against the law to use truck engine brakes in the state of Colorado and there are signs on all of the major roads when entering the state. Why isn’t this law enforced on Highway 184 between Highway 145 and Highway 491?

There are many gravel trucks every day on this stretch of highway and half of them are using engine brakes making very disturbing loud sputtering sounds and disturbing many households.